Bubble cap for gas and liquid contact apparatus



Oct. 7, 1930. c. M; ALEXANDER I 1,777,869

BUBBLE CAP FOR GAS VAND 'LIQUID CONTACT PPARTUS Filed Jan. v18. 1927 HW /y//f/ f. l.

Patented 0a, 7, 1930 I. ALMEXANDER, 0F (')VBIEZANA LOUSIANA ntrBBLn cnr Fon GAS AND LrouIncoN'rAcr Arrennfrus Application led January 18, 1927. Serial No. 161,732.

This invention relates to improvements in gas and liquidor vapor and li uid contact apparatus. More particularly, t e invention yrelates to improvements in bubblecaps such as arev used in VJractionating towers,absorb ing towers, scrubbing towers and the like where itis desired to contact a vapor or gas with a liquid. Towers forthese several purposes are commonly made up of a series of pans or trays in each of which a number of nlpples are arranged, caps being arranged' over the nipples to compel asor vapor rising through the nipple to bubble under the rim or through openings in the side walls of thecap through a pool of liquid maintained on the pan or trayfdverowconnections also being provided to maintain a liquid level at or. above the upper edges of the openings through which the gas or vapor is discharged and to' permit excess liquid to. flow to the next lower an or tray in series. Various sha s of bub le caps have been employed for this purpose, some of them bein 'supported on the rim of the cap and some y a connection between the crown of the cap and the nipple over which it is placed or the tray or pan it-l self, such.connections, for example,'a series.

of webs or lugsbeing arranged to space the bubble cap the desired distance above, and concentric with the axis of the nipple.

This invention provides an improved bubble cap of s ecial value and application in apparatus o the type just described which has several advantages. The improved bubble cap of the invention has a high ratio between the area ofthe 'o enings for the escape of gas or vapor and t e space occupied by the cap, making possible a larger capacity per pan or -tray of a given area. Gas and liquid or vapor and liquid contact apparatus equipped with the improved bubble caps of the invention o'er exceptionally low resistance to the flow of fluids therethrough. The improved bubble .cap of the inventlon also promotes more eective distribution of the gas or vapor escaping therefrom, making ltpossible lto secure better contact between `.i uid and gas or vapor.

n the im roved bubble cap of this invention, the si e walls of the cap are provided with alternate extensions and' indentations with respect vto the mean diameter of the bubble cap and openings forthe escape of gasA and vapor from beneath the ca are arranged throug the side walls both ra ially at the'extremities ofthe extended portions and along the lateral sides thereof .atan angle to the radial axis of said extended portions. The indented portions of the side wall extend inwardly approximately to the nipple over which thebubble cap is arranged So that the' position of the bubble cap is maintained coni centric with that of the nipple Without provision of s ,ecial spacing lugs or. webs. A plurality o Aseries of` openings for-the escape'4 of gas or vaporfrom beneath the cap is thus provided, the several series of openings being arranged to discharge the gas or vapor at substantially different distances from the vertical axis of the bubble cap.

ratio as between the total width of the openy ing and the mean perimeter of the bubble ca is thus maintained, and distribution aifor ing intimate contact is permitted by discharge of the gas or vapor at more or less separated points 'in a manner to insure fine-division of the gas and vapor. The present invention is particularly apy casting as it is, possible to fabricate thebubble' caps in this manner with a relatively large' area of opening for the discharge of gas or vapor with respect to size of the cap without sacrifice of the strength of the cap or` its abilityt'o withstand handling or cooling strains' involved in casting through any necessity of making parts of the cap too light.

Onetforrnl of bubble cap embodying the invention is diagrammatically illustrated inthe accompanying drawing, and the invention will be further described in connection there-Y with, but 'it will be understood th'at while the invention is exemplified by this further description and illustration it is ynot limited thereto. In the drawings:

A higher l licable in connection with bubble caps made Fig. 1 is an elevation, partly in section, of

a 'bubble cap embodying the invention;

Fig. 2 is a plan view, partly in section along the line 2-2 of .the bubble cap shown in of conventional construction such as is commonly used for fractionation, absorption-or scrubbing operations. It consists of a series of trays 6 through which nipples 7 extend. Bubble caps 8 are arranged over the nipples so that gas or vapor rising through the nipples is compelled to bubble through liquid maintained at a level above the discharge openings of the bubble caps by means of runback connections 9 which also serve to convey excess liquid to the next lower tray. Gas or vapor to be supplied to treatment in 'a tower -may, for examplegbe introduced through connection 10 and any gas or vapor remaining uncondensed or unabsorbed may escape through connection 11. Liquid may be supplied through connection 12, and drawn off, .together with any constituents absorbed or condensed from the gas or vapor, through connection 13. Employed as a fractionating tower, hot vapors may be supplied through connection 10, a condensed fraction separated in the tower and drawn o through connection 13, and the uncondensed vapors discharged through connection 11. Employed as a scrubbing or absorption tower, the scrubbing or absorbent medium may be supplied through connection 12 while the gas or vapor mixture to be treated is supplied through connection 10, the absorbent or scrubbing medium char ed with absorbed constituents then being rawn off through connection 13and the stripped gas or vapor mixture through connection 11.

The bubble cap illustrated in the drawing is 0f cast metal. Referring particularly to Figs'. 1 and 2, the side walls are arranged to form a series of extensions 14 and indentations 15, with respect to the mean diameter of the bubble cap, extending vertically the entire height of the bubble-cap. Openings 16 for the escape of gas or vapor are provided at the ends of the extensions 14 and in the lateral side walls. The adjacent openings are thus at a substantially different distance from the vertical axis of the bubble cap and gas or vapor is discharged therefrom in angularly dlreted streams promoting distribution and contact. A larger area of opening is provided than is possible, without sacrifice of the strength of the cap, in a bubble cap of ordinary construction with straight side walls. The indented portions of the sidewalls are not provided with openings for the escape of gas or vapors and extend inwardly approximately to the nip le through which the gas or vapor is intro uced so that no lugs are caps required for centering. Lugs 17 may be provided for vertically s acing the caps the desired distance above tile nipples. In the cap shown these lugs are arranged to permit the lower rim of the bubble cap to extend substantially to the tray. The caps may, however, be supported directly on thelr rim or by the lugs 17 with their lower rim a substantial distance above the tray.

While the bubble caps illustrated can easily be fabricated by casting, and while they are a particularly advantageous form for cast bu ble caps, it will be apparent that bubble embodying the invention can be fabricated in other ways, likewise, that caps of various shapes, square, triangular, hexagonal or rectangular may be constructed embodying the invention.

One of the important advantages of the bubble cap of the invention is that 1t provides for a high ratio between the total width of opening for the discharge ofgas or vapor and the mean perimeter of the bubble cap, or perimeter of a bubble cap of equal size of ordinary construction. Another important advantage of the bubble cap of the invention is that it provides for such distribution of gas or vapor issuing therefrom that any tendency to form large bubbles with consequent reduction of contact surface between gas or vapor and liquid is minimized, insuring better contact and distribution. In one aspect, the improved bubble cap of the invention can be construed as making available for contact with gas or vapor discharge from each cap an annular ring of increased radial thickness of liquid on the tray in which the edge or rim of the cap is submerged. By extending inwardly the indentations in the side walls approximately to the nipple through which gas or vapor is introduced to the bubble cap and providing openings in the lateral sides of the extensions but not in the 'depressions themselves, the innerdiameter of the annular ring of active contacting area is decreased while at the same time the gas or vapor is not required to abruptly reverse its direction of ow so as to increase the frictional resistance to fluid flow therethrough.

I claim: l 1. An improved bubble cap adapted to'tit over a nipple and having side walls with al'- ternate extensions and indentations with' retions with respect t the mean diameterof lthe bubble cap and openings through the extended portions thereof, the indented portions of the side walls extending inwardly to the perimeter of the nipple yover which the bubble cap is placed.

3. An improved bubble cap adapted to fit over a nipple and having side walls with a1- ternate extensions and indentations with respect to the mean diameter of the bubble cap and openings therethrough at substantially different distances from the vertical axis of the cap, the indentations in the side walls extending inwardly to a series of points on the perimeter of a geometrical gure correl sponding to a cross section of the n1 ple over which the bubble cap is to be placed? 4. An improved bubble cap ada ted to it over a nipple and having a series o' openings in the side Walls thereof and another series of openingszprojected a substantial distance beyond the first saidseries of openings, said lside walls having indentationsI therein with respect to the mean diameter of the bubble cap extending'inwardly to a series of points on the perimeter of a geometrical ligure corresponding fto a cross section of the nipple over whic l he bubble cap is to be placed.

5. In g and liquid contact apparatus the improve ent comprising a nipple extending upwar "y from liquid 'n comhination with a bubble cap positioned over said nipple and havin side walls with alternate extensions and in entations with`V respect to the mean diameter of the bubble cap,the indented portions of the side walls extending inwardly to the perimeter of the nipple over which it is placed.

6. An improved bubble cap ada ted to fit over a nipp e and having side wal s with aln ternate extensions and indentations with respect to the mean diameter of'the bubble cap, t e indented portions of which extend inwardly approximately to the perimeter of a geometrical figure corresponding to the cross vsection of the nipple over which thel bubble cap is to be placed, openings in the ends and lateral side walls of said extended portions,

' said extended portions beingarran ed to per mit@J gaseous medium to be transmitted from the crown of the bubble cap to said openings without sudden change lin direction.

In testimony whereof I aix my si ature.

OLIVE M. ALEXAN ER.

a tray adapted to containy 

